Isn't there a way to determine what's causing the check for the .act/.rif files? If the game data is not encrypted, can there be a way to sort of hook the EBOOT and bypass that check? I also noticed "Support Game Purchase" in PARAM.SFO. I thought it might do something but turns out the XMB just ignored it.

I invented this Method to install Addons as full standalone game installations. Yes, that's right some game Addons are full game packages.

How to install a *PSN* debug Addon without the original game.

1. Create a folder with TitleID of the debug patch you want to install / extract.
2. Create a another folder inside of it and call it USRDIR
3. Put any eboot you want inside USRDIR.
4. Copy that folder to //dev_hdd0/game
5. Install the Debug Game Addon from USB media using the Install Package Files in the JB XMB or by some other way.

1. Create a folder with TitleID of the debug patch you want to install / extract.
2. Create a another folder inside of it and call it USRDIR
3. Put any eboot you want inside USRDIR.
4. Copy that folder to //dev_hdd0/game
5. Install the Debug Game Addon from USB media using the Install Package Files in the JB XMB or by some other way.

Yea way back before Sony removed Linux I did this a few times when I upgraded my HDD and was playing with the Linux. I think the issue comes that the system restore formats the HDD and I think part the of DRM needed for these gets stored on the HDD but is never backed up so when you format and restore data it's missing some DRM files.

I've been meaning to test this with a spare HDD and manually FTP system folder back to the HDD but I haven't had time or space to do so. Just got a new 640GB external for extra storage on my system so in a few days I'll have it a try and let you know how it goes.

If it does work it means we have a way to upgrade the internal HDDs with out loosing any PSN content.. though unfortunately if that is the case your basically SOL.